Bioavailability-based risk assessment of various heavy metals via multi-exposure routes for children and teenagers in Beijing, China.

Assessing the health risks of sensitive population, such as children and teenagers, through multiple exposure routes (MERs) such as ingestion, inhalation, and dermal contact is critical for policy creation that protects or reduces exposure to pollutants for all populations. Heavy metal (HM) contents in food and environmental media in Beijing, capital of China, were collected. Furthermore, on the basis of considering the bioavailability of HMs, we evaluated the multiple environmental routes and health risks to HMs in children and teenagers of eight age groups (2-<3, 3-<4, 4-<5, 5-<6, 6-<9, 9-<12, 12-<15, and 15-<18) in Beijing, China by Monte Carlo simulation approach. The main findings are as follows: lead exposure in children aged 2-<3 years exceeds the exposure dose (0.3 µg·kg-1·d-1) of 0.5 point reduction in intelligence quotient. Moreover, children aged 2-<3 and 6-<9 years have relatively high non-carcinogenic risk (NCR) of 1.32 and 1.30, respectively. The carcinogenic risk (CR) for children aged 6-<9 and 9-<12 years is 2.73×10-6 and 2.39×10-6, respectively. Specifically, the contributions of oral ingestion, dermal contact, and inhalation to the NCR were 69.5%, 18.9%, and 11.6%, respectively. Moreover, the combined NCR contributions of copper, cadmium, mercury, and arsenic (As) were about 69.4%. The contributions of the above three routes to the CR were 93.4%, 4.1%, and 2.5%, in that order, with the largest CR contribution of As being about 92.0%. This study can provide new ideas for accurately assessing the exposure and health risks of HMs in the population, and we believe that it is necessary to update the national standards for food and soil based on the bioavailability of HMs.

Evaluation of HPV infection helps to direct ALA-PDT of condyloma acuminata.

BACKGROUND AND OBJECTIVES: Aminolaevulinic acid-mediated photodynamic therapy (ALA-PDT) is increasingly applied for the treatment of condyloma acuminata (CA). However, the determinants for the sessions and end points of ALA-PDT treatment remains unclear. Here, we recorded HPV screening, evaluated the frequency and efficacy of ALA-PDT in different types of CA, in order to individualize ALA-PDT treatment to CA. METHODS: A total of 227 CA patients with HPV infection and visible warts were recruited. Prior to PDT, visible lesions were removed by radio frequency or microwave. HPV DNA detection were performed before each PDT treatment and at follow-up. Treatment was ended after two consecutive negative HPV DNA detection. RESULTS: Of the 227 patients, 119 patients received ALA-PDT and 116 patients completed all treatments. We found that CA patients with multiple-site infection, intra-luminal infection or multiple-type of HPV infection required more sessions of ALA-PDT. The recurrence rate was 8.62% (10/116). Viral load was significantly lower after six PDT treatments compared to viral load after three PDT treatments. Gender, HPV subtypes and warts location had no significant effect on the recurrence rate. CONCLUSION: Comprehensive evaluation of HPV infection state helps to individualize ALA-PDT treatment scheme for CA patients and predict the therapeutic efficacy.

National and provincial dioxin emissions from municipal solid waste incineration in China.

China presently lacks an up-to-date regional inventory of dioxin emissions from municipal solid waste incineration (MSWI), although MSWI has grown rapidly in recent decades. Based on dioxin concentrations from the official website for governments and enterprises, we created an inventory of dioxin emissions from 29 areas in mainland China. MSWI released a total of 22.56 g I-TEQ of dioxins in 2020. According to Monte Carlo simulation, the dioxin emissions with 95 %, 75 %, and 50 % certainty are 17.03-31.62, 19.24-27.71, and 20.43-25.96 g I-TEQ, respectively. Notably, Guangdong, Zhejiang, and Jiangsu provinces accounted for 38.8 %. The primary regions with considerable dioxin emission per capita and density are Zhejiang and Shanghai. Furthermore, Jilin and Heilongjiang provinces are the top two regions in terms of dioxin emissions per unit of billion gross domestic product. These indicators were affected significantly by the quantity of MSW generated and incinerated (MSWGI), capacity and operating years of incinerators, and degrees of air pollution control devices (APCDs). Dioxin emission factors (EFs) were about 100 times lower in 2020 than in 2004. Note, however, that there is a gap in dioxin EFs between China and European nations. We have proposed that MSW source classification, stable operation conditions of incinerators and APCDs, categories of incinerators selection, and technological upgrading should be China's major measures to curb dioxin emissions. Moreover, with the future increment in the quantity of MSWGI, it is essential to completely reinvent the dioxin monitoring program.

Curbing dioxin emissions from municipal solid waste incineration: China's action and global share.

China generates the world's second-largest amount of municipal solid waste (MSW) and incinerates the largest quantity of MSW. However, data on the latest dioxin emissions from MSW incineration (MSWI) and the related global share were lacking. In the context of MSW classification, distinguishing the long-term MSW generation and incineration quantity, and dioxin emissions was necessary for macro-control and policy-making by the Chinese Government. By considering population size and GDP per capita, China's MSW generation toward 2050 was projected based on Monte Carlo simulation. Moreover, dioxin emission factors were also assumed based on the diffusion rate of four grades of air pollution control devices (APCDs). Finally, we show that the quantity of China's MSW generation in 2050 will be 363.50 million tonnes (Mt) with 341.06-382.45 Mt of 75% certainty. China's dioxin emissions from MSWI were approximately 15.46 g I-TEQ in 2019, which accounted for 26.1% of total emissions from global MSWI. We discuss dioxin emission reduction scenarios depending on MSW diversion and APCD upgrades. China's dioxin emissions will be 70.38 g I-TEQ for the business-as-usual scenario, and the dioxin emissions will be 9.29 g I-TEQ (within the range of 8.88-9.64 g I-TEQ) for the optimal scenario in 2050. Moreover, in 2050, the APCD diffusion rate will account for 98.8% of the sensitivity of dioxin emissions from China's MSWI. According to the assumed scenarios, there is a dioxin emission reduction potential of 18.6% and 86.8% in 2050 by MSW diversion alone and maximum APCD upgrades combined with food waste diversion, respectively.

Identification of novel biomarkers and key pathways of condyloma acuminata.

Condyloma acuminata (CA) is a prevalent sexually transmitted disease, associated with human papilloma viruses (HPV) infections and host immune status. In this present study, we aimed to explore immune landscape and biomarkers for CA prevention and treatment. We obtained differentially expressed genes (DEGs) of CA vs normal tissues in GSE140662 and screened out hub genes from the protein-protein interaction (PPI) network. Hub genes were then subjected to microRNA (miRNA) analysis. Besides, CCK-8, transwell, flow cytometry assays were employed to assess the cell proliferation, migration and apoptosis in Hela cells. ImmuCellAI was firstly applied to identify immune cell infiltration levels of CA. We obtained 275 DEGs, 23 hub genes and key miRNAs. Subsequently, we verified four up-regulated hub genes IFIT1, IFI27, OASL, SAMD9L and down-regulated mir-146a-5p in CA tissues by RT-qPCR. Moreover, over-expression of miR-146a-5p reduced Hela cells proliferation, migration, blocked cell cycle and induced apoptosis. Up-regulated miR-146a-5p attenuated PI3K/AKT and activated p38/ MAPK signaling pathway. Proportions of Monocyte, NK cells, Gamma delta cells, Th17 cells were relatively low, while Th1 and CD8+ T cells were relatively high in CA skin. Our study revealed that mir-146a-5p contribute to CA progression through PI3K/AKT and p38/MAPK signaling pathway.

Heavy metal pollution in the soil around municipal solid waste incinerators and its health risks in China.

OBJECTIVE: In China, municipal solid waste (MSW) incineration (MSWI) has been increasing in recent years. However, little is known about how the operation of incinerators can affect levels of heavy metals (HMs) in nearby soils or about the possible associated health risks. It is necessary to understand the degree of enrichment of HMs and health risks to people living nearby. METHODS: Previous studies (2002-2021) regarding soil HMs near MSW incinerators were collected, and a cluster and factor analysis was used to evaluate the accumulation trends and distribution characteritics of HMs. The soil contamination degrees and the consequent health risks were then assessed. RESULTS: Cd (0.24 ± 0.16 mg kg-1) is typically accumulated in the topsoil near incinerators, and this is followed by Hg (0.13 ± 0.09 mg kg-1). Most of the health risk due to the total HMs is derived from dermal contact. Dermal contact with Cd and As contributes to more than 67% of the non-carcinogenic risk, while dermal contact with As contributes to more than 99% of the carcinogenic risk (CR). Furthermore, 81.43% of adult males and 76.85% of adult females suffer from CR levels greater than 10-4 due to dermal exposure to As. CONCLUSIONS: Soils near incinerators indicated light pollution and moderate potential ecological risk, especially with regard to Cd and Hg contamination. Undeniably, there was no significant difference between the health risks from soil HMs near incinerators and from arable land at the national level. It is suggested to reduce the input quantity of HMs by taking advantage of the nationwide implementation of MSW classification and upgrading air pollution control devices for further HM emission reductions.

Fate of dioxins in a municipal solid waste incinerator with state-of-the-art air pollution control devices in China.

The variation of municipal solid waste (MSW) components and the improvement of incinerators have an obvious effect on dioxin emissions. However, there is a knowledge gap on dioxin distribution characteristics following China's implementation of MSW classification. To reveal the fate of dioxins under ultra-low emission standards in leading cities in China, a systematic investigation was carried out in a typical modern MSW incinerator in Shenzhen, China. The dioxin mass balance was built using improved models, which included expanded samples, e.g., the leachate, the raw gas and raw ash from boiler, and the chemicals and residuals from air pollution control devices (APCDs). The results indicated a positive dioxin balance of 0.88 µg I-TEQ/t MSW according to the conventional method containing fly ash, bottom ash, and stack gas. In the new model revealing dioxin characteristics after APCDs, a higher value of 0.89 µg I-TEQ/t MSW was found due to the leachate, slaked lime, and activated carbon-containing dioxins. The distribution of dioxins in output samples of fly ash, bottom ash, stack gas, and leachate were 149.0 %, 41.8 %, 1.6 %, and 0.6 % of MSW, respectively. For incineration itself, the balance was 0.85 µg I-TEQ/t MSW, which indicated the possible release owing to the "memory effect" for the other two methods. This study provided new insight for the accurate estimation of dioxin emissions and a typical case report of MSW incineration with ultra-low dioxin emissions.

Phase distribution of PCDD/Fs in flue gas from municipal solid waste incinerator with ultra-low emission control in China.

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) are the key pollutants of municipal solid waste incineration (MSWI). In this study, the characteristics of 17 toxic 2,3,7,8-substituted congeners in flue gas along six air pollution control devices (APCDs) were investigated in a 400 t/d moving grate furnace located in a typical megacity of Shenzhen, China. The phase distribution and removal efficiency of the different APCDs were analyzed, especially the effect of the selective catalytic reduction (SCR) device. The results showed that PCDD/F TEQs were 59.5%, 67.1%, and 72.5% partitioned into the gas phase (XAD-2 and condensed water) at the economizer outlet, fabric filter outlet, and stack, respectively. Furthermore, the three-year-old catalyst in the SCR tended to remove PCDDs, especially those in the solid phase (filter thimble). More importantly, the PCDF TEQs at the SCR inlet and outlet were 1.045 × 10-3 and 1.568 × 10-3 ng I-TEQ/Nm3, respectively, which meant that the SCR might be ineffective for PCDF TEQ removal. A continuous chlorination of lower chlorinated PCDD/Fs increased the ratio of PCDFs and PCDDs from 0.73 at the SCR inlet to 1.76 at the SCR outlet. This work indicated the asynchronized inefficient removal of PCDD/Fs and nitrogen oxide for this three-year-old catalyst. The obtained results provide suggestions for the entire process of curbing PCDD/F emissions and obtaining ultra-low emission from MSWI.

Toxic element (As and Hg) content and health risk assessment of commercially available rice for residents in Beijing based on their dietary consumption.

Arsenic (As) and mercury (Hg) are toxic elements that are often classified as heavy metals, much like cadmium (Cd) and lead (Pb) and others. In this study, we determined the As and Hg contents in rice samples obtained from commercially available rice in Beijing and the health risks associated with daily dietary exposure to As and Hg by the consumption of this rice. Furthermore, the pollution levels of the rice were evaluated based on the Nemerow index. For this purpose, we collected 353 rice samples from 16 municipal districts in Beijing and determined the As and Hg contents in these samples by microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS). The results were as follows: (i) the average content of As in the collected rice samples was 154.91 µg/kg (95% confidence interval (CI) of 139.90-169.92 µg/kg), and the average content of Hg was 2.02 µg/kg (95% CI of 1.25-2.79 µg/kg), which did not exceed the limits established by China's National Standard; (ii) the Nemerow index indicated that the As and Hg contents in these rice samples were safe; (iii) the dietary exposure to As and Hg by rice consumption was, respectively, 15.35 µg/day and 0.20 µg/day, which accounted for 12.91% and 3.35% of the total dietary exposure, respectively; (iv) the hazard quotients (HQs) of As and Hg by the dietary consumption of rice were, respectively, 0.77 and 0.03, and both the HQ and hazard index (HI is 0.8) were less than one. These results indicate that dietary exposure to As and Hg would have no detrimental effect on the health of the residents in the study area; however, the possible carcinogenesis by As in these residents warrants serious attention.

Content and dietary exposure of cadmium among residents in Northeast China: a case study based on the 5th China Total Diet Study.

Cadmium (Cd), one of the harmful heavy metals, and its accumulation or pollution might cause itai-itai disease. In this study, we investigated the dietary exposure of Cd among residents in Northeast China (including Heilongjiang, Jilin, and Liaoning provinces) and also compared the health risks in adult males in terms of dietary intake. Cd contents in 12 categories of foods were derived from original data from the 5th China Total Diet Study (TDS). The following results were obtained in this study: (i) dietary exposure levels of Cd at the margin of safety (MOS) were 4.55, 1.82, and 2.85 in Heilongjiang, Jilin, and Liaoning provinces, respectively; (ii) the primary dietary sources of Cd included cereals, legumes, potatoes, meat, aquatic products, and vegetables; (iii) Cd contents in the same food category from different regions were not significantly different from the limit of China's National Standards (LCNSs); (iv) dietary exposure of Cd would not have a detrimental effect on the health of residents in Northeast China; (v) we recommend the government to take precedence of the supervision and spot-checking of cereals, legume-nuts, potatoes, meat, aquatic products, vegetables, and alcoholic beverages because of the higher dietary consumption than others; (vi) 99.99% of the Cd content in cereals, legumes, vegetables, meat, and aquatic products sold in Northeast China was less than the LCNSs at the present situation; and (vii) the harmful effects of Cd to human beings are associated with the Cd content in foods and the consumption of such foods.

Assessment of human health risk based on characteristics of potential toxic elements (PTEs) contents in foods sold in Beijing, China.

Metals are generally classified into essential metals groups. Essential metals include copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn), and nonessential metals include cadmium (Cd) and lead (Pb) etc. However, excessive intake of metals even essential metals would have detrimental effect on the body. In this study, seven potential toxic elements (PTEs) (i.e., Cd, Cr, Cu, Fe, Mn, Pb and Zn) and their distribution characteristics in the foods were analyzed as well as the combination of correlation analysis, factor analysis and cluster analysis were constructed. Meanwhile, combined with the dietary consumption data from the Fifth China Total Diet Study (FCTDS), the dietary exposure of PTEs were analyzed and a consequent safety risk assessment was conducted. The main results are as follows: (1) PTE contents in simply-processed samples were found to be lower than those in the highly-processed samples. (2) The average daily intake of the PTEs were about 12.26 (Cd), 153.17 (Cr), 25.16 (Pb) µg/d, 1.90 (Cu), 20.19 (Fe), 7.12 (Mn) and 12.69 (Zn) mg/d, respectively. (3) The total target hazard quotient (TTHQ) was 2.88, which was lower than 10. Therefore, the long-term consumption of these foods combined with the current dietary structure would not have a detrimental effect on the health of residents in Beijing.

Levels of eight heavy metals and health risk assessment considering food consumption by China's residents based on the 5th China total diet study.

The total diet study (TDS) is a significant part of food consumption-based health risk assessment. Since 1990, China has conducted five TDSs based on its unique food culture. In the present study, the health risks of residents from 20 regions of China are assessed by comparing the estimated daily intake (EDI) with adequate intake (AI) for Cr, and the estimated dietary exposure (EDE) with the reference dose (RfD) for seven toxic heavy metals (THMs), which are Al, As, inorganic arsenic (iAs), Cd, Hg, methyl mercury (MeHg), and Pb. The original data were sourced from the 5th China TDS. The data indicated the following: (1) Cereals and vegetables were the main dietary exposure sources of Al, As, iAs, Cd, and Cr; aquatic foods were the important dietary exposure source for As, Hg, and MeHg, especially for the residents from coastal regions. (2) Compared to other elements, Pb had more dietary exposure sources, which included cereals, vegetables, meats, and beverages and water. (3) Potatoes, beverages and water, and meats were the important sources of Al, iAs, and Cr. The results showed that the average level of the dietary intake of Cr was 11 times higher than the AI, as determined from the ratio of EDI to Al. Moreover, the hazard quotients (HQs) of Al, iAs, Cd, Hg, MeHg, and Pb were <1, while that of As (6.49) was >1; therefore, the EDIs of As and Cr by the residents of China are worthy of attention. Additionally, the discrepancies in the dietary exposures of HMs by the residents were due to the different HM contents among different types of foods, and the different dietary structures.

China's carbon dioxide emissions from cement production toward 2030 and multivariate statistical analysis of cement consumption and peaking time at provincial levels.

China, the largest developing country, is the world largest cement producer and the largest cement-consuming nation. Although China's cement output reached its peak in 2014, regions, i.e., Fujian and Yunnan provinces, were no peaking until 2016. At the same time, rare studies referred to China's cement consumption and CO2 emissions from the perspective of cement consumption at the provincial level. We developed the S-Logistic, polynomial model, and ARIMA model to study the peaking time of cement consumption at the provincial level, and we also projected China's cement consumption and CO2 emissions toward 2030. Meanwhile, the discrepancies of peaking time and cumulative cement consumption per capita (CCCPC) among provinces were also studied based on GDP per capita and urbanization rate (UR). The results are that the CCCPC respectively in the range of 22-34 ton, 18-25 ton, and 17-27 ton in the eastern, intermediate, and western zone when cement consumption reached its peak. We draw the following conclusions that the CCCPC in 2030 could reach ~ 43 ton and the projected cement consumption is ~ 1252.72 Mt, which accounts for 50% of that in 2017, and cement CO2 emissions are at the range of 488.19-510.90 MtCO2 in 2030. Furthermore, capacity replacement, controlling new capacity and eliminating backward capacity are significant of greenhouse gas emission reduction not only for China, but also for the global cement industry.

China's cement demand and CO2 emissions toward 2030: from the perspective of socioeconomic, technology and population.

China is the largest cement producer and carbon dioxide (CO2) emitter in the world. The country has attracted too much attention in calculating and comparing its CO2 emissions. However, as the second largest CO2 emitter after the fire power industry, China's long-term cement demand and cement-related CO2 emission projections were not fully studied. The Chinese government, however, committed that by 2020 and 2030, China's per capita GDP of CO2 emissions would be lower than that in 2005 by 40-45% and 60-65%, respectively. In this paper, China's cement demand in 2030 was projected based on the population size, urbanization rate, fixed assets investment, and per capita GDP. Furthermore, decoupling study in China's cement industry was also involved based on the GDP and CO2 emissions during 2001-2015. We also used the diffusion rate of 12 types of CO2 reduction measures and two changed scenarios of clinker-to-cement ratio, to project the cement CO2 emission factors toward 2030 after determining the accounting scope. Meanwhile, the CO2 emissions of China's cement industry through 2030 were projected naturally. The results showed that China's cement output in 2030 will be approximately 2000, 1650, and 937 Mt. based on the fixed assets investment, urbanization rate, and per capita GDP respectively. The projected two scenarios cement CO2 emission factors were resp. 407.83 and 390.02 kg CO2/t of cement which were 42.6 and 45.1% lower than that in 2005. The cement CO2 emissions were projected to be in the range of 366 to 818 Mt. in 2030. Additionally, China's total cement output value has been decoupling from cement CO2 emissions from 2012, which is mainly attributed to eliminating backward capacity, reducing excess capacity or the declining cement output. And decoupling economic from China's cement CO2 emissions may change to be strong or weak decoupling in the near future. As cement production is one of the factors effecting cement CO2 emissions, the most important measure for controlling cement CO2 emissions is a reasonable capacity utilization rate. It is therefore important to control the growth of cement CO2 emissions by regulating the capacity utilization rate within a reasonable range. Eliminating backward capacity, removing excess capacity, controlling new capacity, staggered production, and the "going global" of cement equipment can have great impacts in controlling the total amount of cement output and CO2 emissions.

Empirical assessing cement CO2 emissions based on China's economic and social development during 2001-2030.

Cement industry is a large emitter of carbon dioxide (CO2), taking up 5-8% of anthropogenic CO2 emissions. China is the largest developing country in the world. With the fast urbanization rate, economic growth and rapid development of industry, China's cement production is soaring year by year. Also, cement CO2 emissions increased year by year and aroused the rising attention. However, the historical province- and nation-level cement production situations, driving forces of cement output and/or demand based on rapid economic growth and urbanization rate, the peak of cement consumption and China's cement demand projection and CO2 emissions through 2030 when China should fulfill the international commitments were not clear. The present study summarized the characteristics of China's cement production and CO2 emissions during 2001-2015, projected cement CO2 emission scenarios based on diffusion of alternative materials and technical innovation toward 2030. The following results were summarized, clinker- and cement- CO2 emission factors (EFs) were declining year by year with the technical innovation. CO2 emissions increased with the increase of cement output year by year. The discrepancies of CO2 emissions from different researches were becoming large year by year, and the biggest difference of CO2 emissions reached 49% in 2015. Accordingly, we recommended active EFs for the calculation of cement CO2 emissions. Cement production situation varies greatly with province, as manifested in unbalanced NSP technology and clinker-to-cement ratio, and energy consumption, which was primarily attributed to the unbalanced resource reserves and economic development. There is still sufficient room for CO2 reduction in China's cement industry, and the use of alternative material was better than technical innovation in such reduction. The optimal emissions in 2030 will be 1490 Mt CO2. And China's cement consumption will be stable in 2030, cumulative cement consumption per capita will be peaked at 23394 kg, and UR will reach 70.1%.

Risk of skin cancers in thiopurines-treated and thiopurines-untreated patients with inflammatory bowel disease: A systematic review and meta-analysis.

BACKGROUND AND AIM: The thiopurines are effective in the management of patients with inflammatory bowel disease (IBD), but the association between thiopurines use and the risk of skin cancer (including nonmelanoma skin cancer [NMSC] and melanoma skin cancer) has already been sufficiently reported. However, the results of these studies are inconsistent, and thus, the objective of our analysis was to explore whether thiopurines can lead to an excess risk of skin cancer in IBD patients. METHODS: MEDLINE, EMBASE, and the Cochrane Library were searched to identify relevant studies that evaluated the risk of skin cancer in IBD patients treated with thiopurines. A random effects meta-analysis was conducted to calculate the pooled incidence rate ratios as well as risk ratios (RRs). Subgroup analysis was performed to explore the potential source of heterogeneity. RESULTS: Thirteen studies comprising 149 198 participants were included. The result suggested that thiopurines significantly increased the risk of overall skin cancer in IBD patients (random effects: RR = 1.80, 95% confidence interval [CI] 1.14-2.87, P = 0.013), among which NMSC showed an excess risk associated with thiopurines use (random effects: RR = 1.88, 95% CI 1.48-2.38, P < 0.001) while no increased risk was observed with respect to melanoma skin cancer (random effects: RR = 1.22, 95% CI 0.90-1.65, P = 0.206). Subgroup analysis regarding sample size and geographic distribution in skin cancer and follow-up duration in NMSC reached statistical significance, while other subgroups showed no significance. CONCLUSION: Exposition of thiopurines in patients with IBD is associated with a higher risk of skin cancer. Routine skin screening and daily skin protective practice are recommended for these patients.